/*
    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/util/external/FileUtil.java,v 1.9 2004/08/18 13:12:00 hkollmann Exp $
    * $Revision: 1.9 $
    * $Date: 2004/08/18 13:12:00 $
    *
    * DbForms - a Rapid Application Development Framework
    * Copyright (C) 2001 Joachim Peer <joepeer@excite.com>
    *
    * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   */
  
  /*
   * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/util/external/FileUtil.java,v 1.9 2004/08/18 13:12:00 hkollmann Exp $
   * $Revision: 1.9 $
   * $Date: 2004/08/18 13:12:00 $
   *
   * FileUtil class taken from jakarta-commons-sandbox project.
   *
  **/
  package org.dbforms.util.external;
  
  
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2001 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache" and "Apache Software Foundation" and
   *    "Apache Turbine" must not be used to endorse or promote products
   *    derived from this software without prior written permission. For
   *    written permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    "Apache Turbine", nor may "Apache" appear in their name, without
   *    prior written permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  import java.net.URL;
  
  import java.util.Vector;
  
  
 
 /***
  * DOCUMENT ME!
  *
  * @author $author$
  * @version $Revision: 1.9 $
  */
 public class FileUtil {
    /*** The number of bytes in a kilobyte. */
    public static final int ONE_KB = 1024;
 
    /*** The number of bytes in a megabyte. */
    public static final int ONE_MB = ONE_KB * ONE_KB;
 
    /*** The number of bytes in a gigabyte. */
    public static final int ONE_GB = ONE_KB * ONE_MB;
 
    /* *** AVALON CODE *** */
 
    /***
     * Private constructor to prevent instantiation.
     */
    private FileUtil() {
    }
 
    /***
     * Get extension from filename. ie
     * <pre>
     * foo.txt    --> "txt"
     * a\b\c.jpg --> "jpg"
     * a\b\c     --> ""
     * </pre>
     *
     * @param filename the filename
     *
     * @return the extension of filename or "" if none
     */
    public static String getExtension(final String filename) {
       final int index = filename.lastIndexOf('.');
 
       if (-1 == index) {
          return "";
       } else {
          return filename.substring(index + 1);
       }
    }
 
 
    /***
     * Creates a file handle.
     *
     * @param fileName The name of the file.
     *
     * @return A <code>File</code> instance.
     */
    public static File getFile(String fileName) {
       return new File(fileName);
    }
 
 
    /***
     * Given a directory and an array of extensions... return an array of
     * compliant files. The given extensions should be like "java" and not like
     * ".java"
     *
     * @param directory DOCUMENT ME!
     * @param extensions DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public static String[] getFilesFromExtension(String   directory,
                                                 String[] extensions) {
       Vector       files = new Vector();
 
       java.io.File currentDir = new java.io.File(directory);
 
       String[]     unknownFiles = currentDir.list();
 
       if (unknownFiles == null) {
          return new String[0];
       }
 
       for (int i = 0; i < unknownFiles.length; ++i) {
          String currentFileName = directory
                                   + System.getProperty("file.separator")
                                   + unknownFiles[i];
          java.io.File currentFile = new java.io.File(currentFileName);
 
          if (currentFile.isDirectory()) {
             //ignore all CVS directories...
             if (currentFile.getName()
                                  .equals("CVS")) {
                continue;
             }
 
             //ok... transverse into this directory and get all the files... then combine
             //them with the current list.
             String[] fetchFiles = getFilesFromExtension(currentFileName,
                                                         extensions);
             files = blendFilesToVector(files, fetchFiles);
          } else {
             //ok... add the file
             String add = currentFile.getAbsolutePath();
 
             if (isValidFile(add, extensions)) {
                files.addElement(add);
             }
          }
       }
 
       //ok... move the Vector into the files list...
       String[] foundFiles = new String[files.size()];
       files.copyInto(foundFiles);
 
       return foundFiles;
    }
 
 
    /***
     * Get path from filename. Roughly equivalent to the unix command
     * <code>dirname</code>. ie.
     * <pre>
     * a/b/c.txt --> a/b
     * a.txt     --> ""
     * </pre>
     *
     * @param filepath the filepath
     *
     * @return the filename minus path
     */
    public static String getPath(final String filepath) {
       return getPath(filepath, File.separatorChar);
    }
 
 
    /***
     * Get path from filename. ie.
     * <pre>
     * a/b/c.txt --> a/b
     * a.txt     --> ""
     * </pre>
     *
     * @param filepath the filepath
     * @param fileSeparatorChar DOCUMENT ME!
     *
     * @return the filename minus path
     */
    public static String getPath(final String filepath,
                                 final char   fileSeparatorChar) {
       final int index = filepath.lastIndexOf(fileSeparatorChar);
 
       if (-1 == index) {
          return "";
       } else {
          return filepath.substring(0, index);
       }
    }
 
 
    /***
     * Returns the filename portion of a file specification string. Matches the
     * equally named unix command.
     *
     * @param filename DOCUMENT ME!
     *
     * @return The filename string without extension.
     */
    public static String basename(String filename) {
       return basename(filename, extension(filename));
    }
 
 
    /***
     * Returns the filename portion of a file specification string. Matches the
     * equally named unix command.
     *
     * @param filename DOCUMENT ME!
     * @param suffix DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public static String basename(String filename,
                                  String suffix) {
       int i       = filename.lastIndexOf(File.separator) + 1;
       int lastDot = ((suffix != null) && (suffix.length() > 0))
                     ? filename.lastIndexOf(suffix)
                     : (-1);
 
       if (lastDot >= 0) {
          return filename.substring(i, lastDot);
       } else if (i > 0) {
          return filename.substring(i);
       } else {
          return filename; // else returns all (no path and no extension)
       }
    }
 
 
    /***
     * Returns a human-readable version of the file size (original is in bytes).
     *
     * @param size The number of bytes.
     *
     * @return A human-readable display value (includes units).
     */
    public static String byteCountToDisplaySize(int size) {
       String displaySize;
 
       if ((size / ONE_GB) > 0) {
          displaySize = String.valueOf(size / ONE_GB) + " GB";
       } else if ((size / ONE_MB) > 0) {
          displaySize = String.valueOf(size / ONE_MB) + " MB";
       } else if ((size / ONE_KB) > 0) {
          displaySize = String.valueOf(size / ONE_KB) + " KB";
       } else {
          displaySize = String.valueOf(size) + " bytes";
       }
 
       return displaySize;
    }
 
 
    /***
     * Will concatenate 2 paths.  Paths with &lt;code>..&lt;/code&gt; will be
     * properly handled. &lt;p&gt;Eg.,&lt;br /&gt;
     * &lt;code&gt;/a/b/c&lt;/code&gt; + &lt;code&gt;d&lt;/code&gt; =
     * &lt;code&gt;/a/b/d&lt;/code&gt;&lt;br /&gt;
     * &lt;code&gt;/a/b/c&lt;/code&gt; + &lt;code&gt;../d&lt;/code&gt; =
     * &lt;code&gt;/a/d&lt;/code&gt;&lt;br /&gt; &lt;/p&gt; Thieved from Tomcat
     * sources...
     *
     * @param lookupPath DOCUMENT ME!
     * @param path DOCUMENT ME!
     *
     * @return The concatenated paths, or null if error occurs
     */
    public static String catPath(final String lookupPath,
                                 final String path) {
       // Cut off the last slash and everything beyond
       int    index  = lookupPath.lastIndexOf("/");
       String lookup = lookupPath.substring(0, index);
       String pth    = path;
 
       // Deal with .. by chopping dirs off the lookup path
       while (pth.startsWith("../")) {
          if (lookup.length() > 0) {
             index  = lookup.lastIndexOf("/");
             lookup = lookup.substring(0, index);
          } else {
             // More ..'s than dirs, return null
             return null;
          }
 
          index = pth.indexOf("../") + 3;
          pth   = pth.substring(index);
       }
 
       return new StringBuffer(lookup).append("/")
                                      .append(pth)
                                      .toString();
    }
 
 
    /***
     * Clean a directory without deleting it.
     *
     * @param directory DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void cleanDirectory(final String directory)
                               throws IOException {
       cleanDirectory(new File(directory));
    }
 
 
    /***
     * Clean a directory without deleting it.
     *
     * @param directory DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void cleanDirectory(final File directory)
                               throws IOException {
       if (!directory.exists()) {
          final String message = directory + " does not exist";
          throw new IllegalArgumentException(message);
       }
 
       if (!directory.isDirectory()) {
          final String message = directory + " is not a directory";
          throw new IllegalArgumentException(message);
       }
 
       IOException  exception = null;
 
       final File[] files = directory.listFiles();
 
       for (int i = 0; i < files.length; i++) {
          final File file = files[i];
 
          try {
             forceDelete(file);
          } catch (final IOException ioe) {
             exception = ioe;
          }
       }
 
       if (null != exception) {
          throw exception;
       }
    }
 
 
    /***
     * Compare the contents of two files to determine if they are equal or not.
     *
     * @param file1 the first file
     * @param file2 the second file
     *
     * @return true if the content of the files are equal or they both don't
     *         exist, false otherwise
     *
     * @throws IOException DOCUMENT ME!
     */
    public static boolean contentEquals(final File file1,
                                        final File file2)
                                 throws IOException {
       final boolean file1Exists = file1.exists();
 
       if (file1Exists != file2.exists()) {
          return false;
       }
 
       if (!file1Exists) {
          // two not existing files are equal
          return true;
       }
 
       if (file1.isDirectory() || file2.isDirectory()) {
          // don't want to compare directory contents
          return false;
       }
 
       InputStream input1 = null;
       InputStream input2 = null;
 
       try {
          input1 = new FileInputStream(file1);
          input2 = new FileInputStream(file2);
 
          return IOUtil.contentEquals(input1, input2);
       } finally {
          IOUtil.shutdownStream(input1);
          IOUtil.shutdownStream(input2);
       }
    }
 
 
    /***
     * Copy file from source to destination. The directories up to
     * <code>destination</code> will be created if they don't already exist.
     * <code>destination</code> will be overwritten if it already exists.
     *
     * @param source An existing non-directory <code>File</code> to copy bytes
     *        from.
     * @param destination A non-directory <code>File</code> to write bytes to
     *        (possibly overwriting).
     *
     * @throws IOException if <code>source</code> does not exist,
     *         <code>destination</code> cannot be written to, or an IO error
     *         occurs during copying.
     */
    public static void copyFile(final File source,
                                final File destination)
                         throws IOException {
       //check source exists
       if (!source.exists()) {
          final String message = "File " + source + " does not exist";
          throw new IOException(message);
       }
 
       //does destinations directory exist ?
       if ((destination.getParentFile() != null)
                 && !destination.getParentFile()
                                      .exists()) {
          destination.getParentFile()
                     .mkdirs();
       }
 
       //make sure we can write to destination
       if (destination.exists() && !destination.canWrite()) {
          final String message = "Unable to open file " + destination
                                 + " for writing.";
          throw new IOException(message);
       }
 
       final FileInputStream  input  = new FileInputStream(source);
       final FileOutputStream output = new FileOutputStream(destination);
       IOUtil.copy(input, output);
       IOUtil.shutdownStream(input);
       IOUtil.shutdownStream(output);
 
       if (source.length() != destination.length()) {
          final String message = "Failed to copy full contents from " + source
                                 + " to " + destination;
          throw new IOException(message);
       }
    }
 
 
    /***
     * Copy file from source to destination. If
     * <code>destinationDirectory</code> does not exist, it (and any parent
     * directories) will be created. If a file <code>source</code> in
     * <code>destinationDirectory</code> exists, it will be overwritten.
     *
     * @param source An existing <code>File</code> to copy.
     * @param destinationDirectory A directory to copy <code>source</code> into.
     *
     * @throws IOException if <code>source</code> does not exist, the file in
     *         <code>destinationDirectory</code> cannot be written to, or an IO
     *         error occurs during copying.
     */
    public static void copyFileToDirectory(final String source,
                                           final String destinationDirectory)
                                    throws IOException {
       copyFileToDirectory(new File(source), new File(destinationDirectory));
    }
 
 
    /***
     * Copy file from source to destination. If
     * <code>destinationDirectory</code> does not exist, it (and any parent
     * directories) will be created. If a file <code>source</code> in
     * <code>destinationDirectory</code> exists, it will be overwritten.
     *
     * @param source An existing <code>File</code> to copy.
     * @param destinationDirectory A directory to copy <code>source</code> into.
     *
     * @throws IOException if <code>source</code> does not exist, the file in
     *         <code>destinationDirectory</code> cannot be written to, or an IO
     *         error occurs during copying.
     */
    public static void copyFileToDirectory(final File source,
                                           final File destinationDirectory)
                                    throws IOException {
       if (destinationDirectory.exists() && !destinationDirectory.isDirectory()) {
          throw new IllegalArgumentException("Destination is not a directory");
       }
 
       copyFile(source, new File(destinationDirectory, source.getName()));
    }
 
 
    /***
     * Copies bytes from the URL <code>source</code> to a file
     * <code>destination</code>. The directories up to <code>destination</code>
     * will be created if they don't already exist. <code>destination</code>
     * will be overwritten if it already exists.
     *
     * @param source A <code>URL</code> to copy bytes from.
     * @param destination A non-directory <code>File</code> to write bytes to
     *        (possibly overwriting).
     *
     * @throws IOException if <ul><li><code>source</code> URL cannot be
     *         opened</li> <li><code>destination</code> cannot be written
     *         to</li> <li>an IO error occurs during copying</li> </ul>
     */
    public static void copyURLToFile(final URL  source,
                                     final File destination)
                              throws IOException {
       //does destination directory exist ?
       if ((destination.getParentFile() != null)
                 && !destination.getParentFile()
                                      .exists()) {
          destination.getParentFile()
                     .mkdirs();
       }
 
       //make sure we can write to destination
       if (destination.exists() && !destination.canWrite()) {
          final String message = "Unable to open file " + destination
                                 + " for writing.";
          throw new IOException(message);
       }
 
       final InputStream      input  = source.openStream();
       final FileOutputStream output = new FileOutputStream(destination);
       IOUtil.copy(input, output);
       IOUtil.shutdownStream(input);
       IOUtil.shutdownStream(output);
    }
 
 
    /***
     * Recursively delete a directory.
     *
     * @param directory DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void deleteDirectory(final String directory)
                                throws IOException {
       deleteDirectory(new File(directory));
    }
 
 
    /***
     * Recursively delete a directory.
     *
     * @param directory DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void deleteDirectory(final File directory)
                                throws IOException {
       if (!directory.exists()) {
          return;
       }
 
       cleanDirectory(directory);
 
       if (!directory.delete()) {
          final String message = "Directory " + directory
                                 + " unable to be deleted.";
          throw new IOException(message);
       }
    }
 
 
    /***
     * Returns the directory path portion of a file specification string.
     * Matches the equally named unix command.
     *
     * @param filename DOCUMENT ME!
     *
     * @return The directory portion excluding the ending file separator.
     */
    public static String dirname(String filename) {
       int i = filename.lastIndexOf(File.separator);
 
       return ((i >= 0) ? filename.substring(0, i)
                        : "");
    }
 
 
    /***
     * Returns the extension portion of a file specification string. This
     * everything after the last dot '.' in the filename (NOT including the
     * dot).
     *
     * @param filename DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public static String extension(String filename) {
       int lastDot = filename.lastIndexOf('.');
 
       if (lastDot >= 0) {
          return filename.substring(lastDot + 1);
       } else {
          return "";
       }
    }
 
 
    /***
     * Copy a file. The new file will be created if it does not exist. This is
     * an inefficient method, which just calls {@link #fileRead(String)} and
     * then {@link #fileWrite(String,String)}
     *
     * @param inFileName the file to copy
     * @param outFileName the file to copy to
     *
     * @throws Exception if fileRead or fileWrite throw it
     */
    public static void fileCopy(String inFileName,
                                String outFileName) throws Exception {
       String content = fileRead(inFileName);
       fileWrite(outFileName, content);
    }
 
 
    /***
     * Deletes a file.
     *
     * @param fileName The name of the file to delete.
     */
    public static void fileDelete(String fileName) {
       File file = new File(fileName);
       file.delete();
    }
 
 
    /***
     * Check if a file exits.
     *
     * @param fileName The name of the file to check.
     *
     * @return true if file exists.
     */
    public static boolean fileExists(String fileName) {
       File file = new File(fileName);
 
       return file.exists();
    }
 
 
    /***
     * Reads the contents of a file.
     *
     * @param fileName The name of the file to read.
     *
     * @return The file contents or null if read failed.
     *
     * @throws IOException DOCUMENT ME!
     */
    public static String fileRead(String fileName) throws IOException {
       StringBuffer    buf = new StringBuffer();
 
       FileInputStream in = new FileInputStream(fileName);
 
       try {
          int    count;
          byte[] b = new byte[512];
 
          while ((count = in.read(b)) > 0) // blocking read
           {
             buf.append(new String(b, 0, count));
          }
       } finally {
          in.close();
       }
 
       return buf.toString();
    }
 
 
    /***
     * Writes data to a file. The file will be created if it does not exist.
     *
     * @param fileName The name of the file to write.
     * @param data The content to write to the file.
     *
     * @throws Exception DOCUMENT ME!
     */
    public static void fileWrite(String fileName,
                                 String data) throws Exception {
       FileOutputStream out = new FileOutputStream(fileName);
 
       try {
          out.write(data.getBytes());
       } finally {
          out.close();
       }
    }
 
 
    /***
     * Returns the filename portion of a file specification string.
     *
     * @param filename DOCUMENT ME!
     *
     * @return The filename string with extension.
     */
    public static String filename(String filename) {
       int i = filename.lastIndexOf(File.separator);
 
       return ((i >= 0) ? filename.substring(i + 1)
                        : filename);
    }
 
 
    /***
     * Delete a file. If file is directory delete it and all sub-directories.
     *
     * @param file DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void forceDelete(final String file) throws IOException {
       forceDelete(new File(file));
    }
 
 
    /***
     * Delete a file. If file is directory delete it and all sub-directories.
     *
     * @param file DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void forceDelete(final File file) throws IOException {
       if (file.isDirectory()) {
          deleteDirectory(file);
       } else {
          if (!file.delete()) {
             final String message = "File " + file + " unable to be deleted.";
             throw new IOException(message);
          }
       }
    }
 
 
    /***
     * Schedule a file to be deleted when JVM exits. If file is directory delete
     * it and all sub-directories.
     *
     * @param file DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void forceDeleteOnExit(final File file)
                                  throws IOException {
       if (file.isDirectory()) {
          deleteDirectoryOnExit(file);
       } else {
          file.deleteOnExit();
       }
    }
 
 
    /***
     * Make a directory. If there already exists a file with specified name or
     * the directory is unable to be created then an exception is thrown.
     *
     * @param file DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public static void forceMkdir(final File file) throws IOException {
       if (file.exists()) {
          if (file.isFile()) {
             final String message = "File " + file + " exists and is "
                                    + "not a directory. Unable to create directory.";
             throw new IOException(message);
          }
       } else {
          if (false == file.mkdirs()) {
             final String message = "Unable to create directory " + file;
             throw new IOException(message);
          }
       }
    }
 
 
    /***
     * Simple way to make a directory
     *
     * @param dir DOCUMENT ME!
     */
    public static void mkdir(String dir) {
       File file = new File(dir);
 
       if (!file.exists()) {
          file.mkdirs();
       }
    }
 
 
    /***
     * Normalize a path. Eliminates "/../" and "/./" in a string. Returns
     * <code>null</code> if the ..'s went past the root. Eg:
     * <pre>
     * /foo//               -->     /foo/
     * /foo/./              -->     /foo/
     * /foo/../bar          -->     /bar
     * /foo/../bar/         -->     /bar/
     * /foo/../bar/../baz   -->     /baz
     * //foo//./bar         -->     /foo/bar
     * /../                 -->     null
     * </pre>
     *
     * @param path the path to normalize
     *
     * @return the normalized String, or <code>null</code> if too many ..'s.
     */
    public static String normalize(final String path) {
       String normalized = path;
 
       // Resolve occurrences of "//" in the normalized path
       while (true) {
          int index = normalized.indexOf("//");
 
          if (index < 0) {
             break;
          }
 
          normalized = normalized.substring(0, index)
                       + normalized.substring(index + 1);
       }
 
       // Resolve occurrences of "/./" in the normalized path
       while (true) {
          int index = normalized.indexOf("/./");
 
          if (index < 0) {
             break;
          }
 
          normalized = normalized.substring(0, index)
                       + normalized.substring(index + 2);
       }
 
       // Resolve occurrences of "/../" in the normalized path
       while (true) {
          int index = normalized.indexOf("/../");
 
          if (index < 0) {
             break;
          }
 
          if (index == 0) {
             return null; // Trying to go outside our context
          }
 
          int index2 = normalized.lastIndexOf('/', index - 1);
          normalized = normalized.substring(0, index2)
                       + normalized.substring(index + 3);
       }
 
       // Return the normalized path that we have completed
       return normalized;
    }
 
 
    /***
     * Remove extension from filename. ie
     * <pre>
     * foo.txt    --> foo
     * a\b\c.jpg --> a\b\c
     * a\b\c     --> a\b\c
     * </pre>
     *
     * @param filename the filename
     *
     * @return the filename minus extension
     */
    public static String removeExtension(final String filename) {
       final int index = filename.lastIndexOf('.');
 
       if (-1 == index) {
          return filename;
       } else {
          return filename.substring(0, index);
       }
    }
 
 
    /***
     * Remove path from filename. Equivalent to the unix command
     * <code>basename</code> ie.
     * <pre>
     * a/b/c.txt --> c.txt
     * a.txt     --> a.txt
     * </pre>
     *
     * @param filepath the filepath
     *
     * @return the filename minus path
     */
    public static String removePath(final String filepath) {
       return removePath(filepath, File.separatorChar);
    }
 
 
    /***
     * Remove path from filename. ie.
     * <pre>
     * a/b/c.txt --> c.txt
     * a.txt     --> a.txt
     * </pre>
     *
     * @param filepath the filepath
     * @param fileSeparatorChar DOCUMENT ME!
     *
     * @return the filename minus path
     */
    public static String removePath(final String filepath,
                                    final char   fileSeparatorChar) {
       final int index = filepath.lastIndexOf(fileSeparatorChar);
 
       if (-1 == index) {
          return filepath;
       } else {
          return filepath.substring(index + 1);
       }
    }
 
 
    /***
     * Resolve a file <code>filename</code> to it's canonical form. If
     * <code>filename</code> is relative (doesn't start with <code>/</code>),
     * it will be resolved relative to <code>baseFile</code>, otherwise it is
     * treated as a normal root-relative path.
     *
     * @param baseFile Where to resolve <code>filename</code> from, if
     *        <code>filename</code> is relative.
     * @param filename Absolute or relative file path to resolve.
     *
     * @return The canonical <code>File</code> of <code>filename</code>.
     */
    public static File resolveFile(final File baseFile,
                                   String     filename) {
       String filenm = filename;
 
       if ('/' != File.separatorChar) {
          filenm = filename.replace('/', File.separatorChar);
       }
 
       if ('//' != File.separatorChar) {
          filenm = filename.replace('//', File.separatorChar);
       }
 
       // deal with absolute files
       if (filenm.startsWith(File.separator)) {
          File file = new File(filenm);
 
          try {
             file = file.getCanonicalFile();
          } catch (final IOException ioe) {
             ;
          }
 
          return file;
       }
 
       // FIXME: I'm almost certain this // removal is unnecessary, as getAbsoluteFile() strips
       // them. However, I'm not sure about this UNC stuff. (JT)
       final char[]       chars = filename.toCharArray();
       final StringBuffer sb = new StringBuffer();
 
       //remove duplicate file separators in succession - except
       //on win32 at start of filename as UNC filenames can
       //be //AComputer\AShare\myfile.txt
       int start = 0;
 
       if ('//' == File.separatorChar) {
          sb.append(filenm.charAt(0));
          start++;
       }
 
       for (int i = start; i < chars.length; i++) {
          final boolean doubleSeparator = (File.separatorChar == chars[i])
                                          && (File.separatorChar == chars[i - 1]);
 
          if (!doubleSeparator) {
             sb.append(chars[i]);
          }
       }
 
       filenm = sb.toString();
 
       //must be relative
       File file = (new File(baseFile, filenm)).getAbsoluteFile();
 
       try {
          file = file.getCanonicalFile();
       } catch (final IOException ioe) {
          ;
       }
 
       return file;
    }
 
 
    /***
     * Recursively count size of a directory.
     *
     * @param directory DOCUMENT ME!
     *
     * @return size of directory in bytes.
     */
    public static long sizeOfDirectory(final String directory) {
       return sizeOfDirectory(new File(directory));
    }
 
 
    /***
     * Recursively count size of a directory.
     *
     * @param directory DOCUMENT ME!
     *
     * @return size of directory in bytes.
     */
    public static long sizeOfDirectory(final File directory) {
       if (!directory.exists()) {
          final String message = directory + " does not exist";
          throw new IllegalArgumentException(message);
       }
 
       if (!directory.isDirectory()) {
          final String message = directory + " is not a directory";
          throw new IllegalArgumentException(message);
       }
 
       long         size = 0;
 
       final File[] files = directory.listFiles();
 
       for (int i = 0; i < files.length; i++) {
          final File file = files[i];
 
          if (file.isDirectory()) {
             size += sizeOfDirectory(file);
          } else {
             size += file.length();
          }
       }
 
       return size;
    }
 
 
    /***
     * Convert from a <code>URL</code> to a <code>File</code>.
     *
     * @param url File URL.
     *
     * @return The equivalent <code>File</code> object, or <code>null</code> if
     *         the URL's protocol is not <code>file</code>
     */
    public static File toFile(final URL url) {
       if (url.getProtocol()
                    .equals("file") == false) {
          return null;
       } else {
          final String filename = url.getFile()
                                     .replace('/', File.separatorChar);
 
          return new File(filename);
       }
    }
 
 
    /***
     * Convert the array of Files into a list of URLs.
     *
     * @param files the array of files
     *
     * @return the array of URLs
     *
     * @throws IOException if an error occurs
     */
    public static URL[] toURLs(final File[] files) throws IOException {
       final URL[] urls = new URL[files.length];
 
       for (int i = 0; i < urls.length; i++) {
          urls[i] = files[i].toURL();
       }
 
       return urls;
    }
 
 
    /***
     * Waits for NFS to propagate a file creation, imposing a timeout.
     *
     * @param fileName The name of the file.
     * @param seconds The maximum time in seconds to wait.
     *
     * @return True if file exists.
     */
    public static boolean waitFor(String fileName,
                                  int    seconds) {
       File file    = new File(fileName);
       int  timeout = 0;
       int  tick    = 0;
 
       while (!file.exists()) {
          if (tick++ >= 10) {
             tick = 0;
 
             if (timeout++ > seconds) {
                return false;
             }
          }
 
          try {
             Thread.sleep(100);
          } catch (InterruptedException ignore) {
             ;
          } catch (Exception ex) {
             break;
          }
       }
 
       return true;
    }
 
 
    /***
     * Checks to see if a file is of a particular type(s). Note that if the file
     * does not have an extension, an empty string (&quot;&quot;) is matched
     * for.
     *
     * @param file DOCUMENT ME!
     * @param extensions DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    private static boolean isValidFile(String   file,
                                       String[] extensions) {
       String extension = extension(file);
 
       if (extension == null) {
          extension = "";
       }
 
       //ok.. now that we have the "extension" go through the current know
       //excepted extensions and determine if this one is OK.
       for (int i = 0; i < extensions.length; ++i) {
          if (extensions[i].equals(extension)) {
             return true;
          }
       }
 
       return false;
    }
 
 
    /***
     * Private hepler method for getFilesFromExtension()
     *
     * @param v DOCUMENT ME!
     * @param files DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    private static Vector blendFilesToVector(Vector   v,
                                             String[] files) {
       for (int i = 0; i < files.length; ++i) {
          v.addElement(files[i]);
       }
 
       return v;
    }
 
 
    /***
     * Clean a directory without deleting it.
     *
     * @param directory DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     * @throws IllegalArgumentException DOCUMENT ME!
     */
    private static void cleanDirectoryOnExit(final File directory)
                                      throws IOException {
       if (!directory.exists()) {
          final String message = directory + " does not exist";
          throw new IllegalArgumentException(message);
       }
 
       if (!directory.isDirectory()) {
          final String message = directory + " is not a directory";
          throw new IllegalArgumentException(message);
       }
 
       IOException  exception = null;
 
       final File[] files = directory.listFiles();
 
       for (int i = 0; i < files.length; i++) {
          final File file = files[i];
 
          try {
             forceDeleteOnExit(file);
          } catch (final IOException ioe) {
             exception = ioe;
          }
       }
 
       if (null != exception) {
          throw exception;
       }
    }
 
 
    /***
     * Recursively schedule directory for deletion on JVM exit.
     *
     * @param directory DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    private static void deleteDirectoryOnExit(final File directory)
                                       throws IOException {
       if (!directory.exists()) {
          return;
       }
 
       cleanDirectoryOnExit(directory);
       directory.deleteOnExit();
    }
 }